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Smart Solar 75/15 connected thru breaker to Solbian 130w panel. Bright sunny day, can only charge at about 50% max rate. Battery (200ah) about 5% drained and charger bulk charges until absorption stage. But again only about 4a vs about 8a -10a max. Could this be a slower bulk charge rate since battery is so slightly discharged? Or as I understand, bulk should charge at max rate no matter battery almost fully discharged vs slightly discharged.
Hi,
What voltage is your solar panel? Generally its best to have the panel deliver higher volts than the battery string. E.g. using a 12v Battery with 24v Solar panels, which will give around 40-44 volts in bright sun.
This difference is used by the MPPT to better regulate voltage, and to have enough room in the voltage range as sunlight varies. Also allows you to start charging earlier in the day.
Also remember batteries pull from the charger, the charger doesnt push current in.
BTW, I am not an expert and am commenting here for my own understanding too.
I believe you are right that the bulk charge will occur at constant amps but rising voltage as the battery fills during bulk stage.
My understanding of low amps during bulk charge can be an indicator of poor battery health.
How old is you battery and what type of chemistry is it?
Alex
